The purpose of this Academic Research Enhancement Award application is to train personnel in the methods of cardiac modeling and obtain the research support necessary to apply these methods to cardiopulmonary patterns during sleep apnea in seal pups. The essence of the proposal is that heart rate patterns during sleep apnea in seals are complex and related to the ability of the seals to tolerate long duration breath-holds. However, in order to compare these seal patterns to human cardiac rhythm dynamics that occur during sleep apnea disorder and children at risk for SIDS, the use of sophisticated time-based analysis of heart rate is required. Seals routinely hold their breath while sleeping and elephant seal pups can tolerate apnea as long as 13-14 min. Sleep apnea in seal pups is central, repetitive, under developmental influence and, most importantly, normal and non-pathogenic. During these periods, seals exhibit a suite of physiological and metabolic events that include heart rate changes, significant circulatory oxygen desaturation, dramatic hematocrit and peripheral circulatory flow alterations. Dr. Castellini has studied the metabolic implications of sleep apnea in seals for the last five years and has recently found that heart rate patterns appear similar to children that are at risk for SIDS. Most of Dr. Castellini's training has been in biochemistry and physiological regulation. Statistical modeling of time-based rhythm changes, such as occur in heart rate, is a new field of endeavor. This enhancement application is to bring those methods to his laboratory and to apply them to the phenomenon of sleep apnea in seals. The project is composed of a training section, equipment acquisition and experimental tests on several species of seals.